WO2017018368A1 - Shock absorber - Google Patents

Abstract

A shock absorber A comprising: a shock absorber main body 1; a spring bearing 21 supporting one end of a suspension spring 2 and capable of moving in the axial direction of the shock absorber main body 1; a jack 3 having a housing 33 attached to the shock absorber main body 1 and a piston 34 movably provided in the housing 33 and forming a liquid chamber L between same and the housing 33; an auxiliary spring 22 interposed between the spring bearing 21 and the piston 34; and a spacer 4 provided parallel to the auxiliary spring 22 and having a length in the axial direction that is longer than the solid height of the auxiliary spring 22.

Description

Shock absorber

The present invention relates to a shock absorber.

Conventionally, the shock absorber is used to support the rear wheel of a straddle-type vehicle such as a motorcycle or a tricycle. Among such shock absorbers, there is one in which a spring support that supports one end of a suspension spring, which is a coil spring, is driven by a jack so that the vehicle height can be adjusted (for example, JP2010-149548A).

Here, when increasing the vehicle height adjustment amount in the shock absorber, it is preferable to increase the vehicle height adjustment amount without changing the suspension spring. This is because the suspension spring has already been optimally designed, and it is complicated to redesign the suspension spring. However, in the conventional shock absorber, if the vehicle height adjustment amount is increased without changing the suspension spring, no load is applied to the suspension spring when the shock absorber is fully extended, and the suspension spring can move freely in the axial direction. The state, i.e., the suspension spring may be idle.

For this reason, the applicant can insert an auxiliary spring between the jack and the spring receiver, and even if the height adjustment amount is increased without changing the longitudinal dimension of the suspension spring, the buffer that can prevent the suspension spring from playing. Proposed a vessel.

In such a shock absorber, when the spring constant of the auxiliary spring is significantly smaller than the spring constant of the suspension spring so that the auxiliary spring that is a coil spring has a close contact height in the state of being attached to the stopped vehicle, During normal vehicle travel, the auxiliary spring is maintained in a close contact height, so that the vehicle body can be elastically supported only by the suspension spring. However, in such a case, when an impact due to road surface unevenness is input, since the auxiliary spring receives a load in a close contact height, the coils constituting the auxiliary spring rub against each other to paint the auxiliary spring. There is a risk of peeling and poor appearance. Further, depending on the load received by the auxiliary spring in the contact height state, a stress greater than the allowable stress may act on the wire constituting the auxiliary spring.

An object of the present invention is to suppress the appearance failure of the auxiliary spring and to prevent excessive stress from acting on the auxiliary spring.

According to an aspect of the present invention, a shock absorber body, a spring receiver that supports one end of a suspension spring and is movable in the axial direction of the shock absorber body, a housing attached to the shock absorber body, and the housing A jack having a piston that is movably provided and forms a liquid chamber with the housing, an auxiliary spring interposed between the spring receiver and the piston, and provided in parallel with the auxiliary spring. And a spacer whose axial length is longer than the contact height of the auxiliary spring.

FIG. 1 is a side view schematically showing a vehicle equipped with a shock absorber according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view showing a no-load state of the shock absorber according to the embodiment of the present invention, showing a state where the piston is advanced to the maximum on the right side of the center line, and a maximum retracting of the piston on the left side of the center line Shows the state. FIG. 3 is a partial cross-sectional view showing a 1G state of the shock absorber according to the embodiment of the present invention, showing a state in which the piston is advanced to the maximum on the right side of the center line, and retracting the piston to the maximum on the left side of the center line. Indicates the state. FIG. 4 is an enlarged view of a part of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a shock absorber A according to an embodiment of the present invention is interposed between a vehicle body B and a rear wheel W of a vehicle V that is a motorcycle. As shown in FIG. 2, the shock absorber A includes a shock absorber body 1, a suspension spring 2 provided on the outer periphery of the shock absorber body 1, a spring receiver 20 that supports the lower end of the suspension spring 2 in FIG. The spring receiver 21 that supports the upper end of the spring 2 in FIG. 2, the jack 3 that adjusts the position of the spring receiver 21, the auxiliary spring 22 interposed between the spring receiver 21 and the jack 3, and the auxiliary spring 22 in parallel. And a spacer 4 provided on the surface.

The shock absorber body 1 includes a cylindrical outer shell 10 and a rod 11 that is movably inserted into the outer shell 10, and has a damping force that suppresses relative movement of the outer shell 10 and the rod 11 in the axial direction. appear. Brackets 12 and 13 are fixed to the outer shell 10 and the rod 11, respectively. The bracket 12 on the outer shell 10 side is connected to the vehicle body B, and the bracket 13 on the rod 11 side is connected to a swing arm b1 (see FIG. 1) that supports the rear wheel W via a link (not shown). Therefore, when an impact caused by road surface unevenness is input to the rear wheel W, the rod 11 enters and exits the outer shell 10 and the shock absorber body 1 expands and contracts to generate a damping force. As a result of expansion and contraction of the suspension spring 2 and the auxiliary spring 22 together with the shock absorber main body 1, the shock absorber A expands and contracts.

The suspension spring 2 is a coil spring formed by winding a wire in a coil shape, and exhibits an elastic force that resists compression when compressed. The spring receiver 20 that supports the lower end of the suspension spring 2 in FIG. 2 is formed in an annular shape and provided on the outer periphery of the rod 11, and the downward movement of the rod 11 in FIG. A spring receiver 21 that supports the upper end of the suspension spring 2 in FIG. 2 is formed in an annular shape and provided on the outer periphery of the outer shell 10, and is supported by the jack 3 via the auxiliary spring 22 or the auxiliary spring 22 and the spacer 4. It is done.

A flange 14 that protrudes outward is fixed to the outer periphery of the upper end portion of the outer shell 10 in FIG. The outer periphery of the outer shell 10 in the lower side in FIG. 2 than the flange 14 is covered with a cylindrical guide 15. A spring receiver 21 is slidably provided on the outer periphery of the guide 15, and the spring receiver 21 is movable in the axial direction of the outer shell 10. The guide 15 is formed with annular grooves (not shown) along the circumferential direction at both ends in the axial direction, and snap rings 16 and 17 are fitted into the annular grooves. On the outer periphery of the guide 15, a spring receiver 21, an auxiliary spring 22, and a jack main body 30, which will be described later, of the jack 3 are provided side by side in order from the lower side in FIG. .

Jack 3 is for adjusting the vehicle height. The jack 3 includes a jack body 30, a pump 31 that supplies hydraulic oil to the jack body 30, and a motor 32 that drives the pump 31. The pump 31 and the motor 32 may have any configuration, and a well-known configuration can be adopted, and thus detailed description thereof is omitted. When the pump 31 is a gear pump, the pump 31 is inexpensive and excellent in durability, and the hydraulic oil can be quickly supplied to the jack body 30.

The jack body 30 includes a bottomed cylindrical housing 33 and an annular piston 34 that is movable along the outer periphery of the guide 15. The housing 33 includes an annular base 33a provided on the outer periphery of the guide 15, and a cylindrical portion 33b extending downward from the outer periphery of the base 33a in FIG. The piston 34 is slidably inserted into the cylindrical portion 33 b of the housing 33. Between the base portion 33a and the guide 15, between the piston 34 and the guide 15, and between the piston 34 and the cylindrical portion 33b are respectively closed by annular O-rings (not shown). An annular space surrounded by the base portion 33a, the cylindrical portion 33b, the piston 34, and the guide 15 serves as a liquid chamber L, and is filled with hydraulic oil.

The liquid chamber L is connected to the pump 31 via a hose or the like. When the hydraulic oil is supplied to the liquid chamber L by the pump 31, the piston 34 advances downward in FIG. 2 and the liquid chamber L expands. On the contrary, when the hydraulic oil is discharged from the liquid chamber L by the pump 31, the piston 34 moves backward in FIG. 2 and the liquid chamber L is reduced.

The auxiliary spring 22 which is the outer periphery of the guide 15 and is interposed between the jack body 30 and the spring receiver 21 is a coil spring formed by winding a wire in a coil shape, and resists compression when compressed. Demonstrate elasticity. The auxiliary spring 22 is supported at its lower end in FIG. 2 by a spring receiver 21 and at its upper end in FIG.

The spacer 4 provided in parallel with the auxiliary spring 22 is formed in a cylindrical shape and connected to the lower end of the piston 34 in FIG. The inner diameter of the spacer 4 is equal to or greater than the outer diameter of the auxiliary spring 22, and the auxiliary spring 22 is inserted inside the spacer 4. The outer diameter of the spacer 4 is equal to or smaller than the outer diameter of the piston 34, and the inner diameter of the auxiliary spring 22 is equal to or larger than the inner diameter of the piston 34. Therefore, when the piston 34 moves backward, the auxiliary spring 22 enters the cylindrical portion 33b together with the spacer 4 while being supported by the piston 34, as shown on the left side in FIG.

2, the spring receiver 21 that supports the lower end of the auxiliary spring 22 in FIG. 2 supports the upper end of the suspension spring 2 in FIG. 2 and is movable in the axial direction of the outer shell 10. The auxiliary spring 22 and the suspension spring 2 are connected in series via a spring receiver 21.

When the spring member S is composed of the suspension spring 2, the spring receiver 21 and the auxiliary spring 22 connected in series as described above, the elastic force of the spring member S acts on the piston 34 and the housing 33 of the jack body 30. Is pressed against the flange 14. Further, the housing 33 of the jack body 30 is prevented from coming off from the guide 15 by the upper snap ring 17 in FIG. Therefore, when the jack body 30 is pressed against the flange 14 by the elastic force of the spring member S, the axial movement of the guide 15 relative to the outer shell 10 is restricted by the snap ring 17 and the flange 14. Further, since the elastic force of the spring member S also acts on the lower spring receiver 20 in FIG. 2, the spring receiver 20 is pressed against the bracket 13 by the elastic force of the spring member S. Therefore, when the shock absorber body 1 expands and contracts, the spring member S expands and contracts, and the vehicle body B is elastically supported by the spring member S.

FIG. 2 shows the shock absorber A in an unloaded state where no load is applied. In this unloaded state, the shock absorber A has a natural length, and the shock absorber main body 1 is fully extended. In FIG. 2, the state where the piston 34 has advanced a maximum is shown on the right side of the center line, and the state where the piston 34 has retracted a maximum is shown on the left side of the center line.

As shown on the right side in FIG. 2, in the state where the piston 34 is advanced to the maximum in the no-load state, the auxiliary spring 22 deflects the suspension spring 2 by a certain amount to give an initial deflection, and applies a predetermined initial load to the suspension spring 2. Call.

The spring receiver 21 does not interfere with the lower snap ring 16 in FIG. 2 in the assembled state of the shock absorber A even when the piston 34 is advanced as much as possible. When the snap ring 16 is provided, it is possible to prevent the spring receiver 21 from coming out of the guide 15 due to the elastic force of the auxiliary spring 22 during the assembly process of the shock absorber A. Therefore, the work of assembling the shock absorber A can be facilitated. . However, after the assembly of the shock absorber A is completed, the snap ring 16 does not interfere with the spring receiver 21 and does not hinder the movement of the spring receiver 21.

As shown on the left side in FIG. 2, in the state where the piston 34 is retracted to the maximum in the no-load state, the piston 34 abuts on the base portion 33a of the housing 33, and the suspension spring 2 and the auxiliary spring 22 are of natural length (free height). Close to. An annular recess 34a is provided on the outer peripheral side of the upper end of the piston 34 in FIG. 2 (FIG. 4), and the recess 34a faces the opening of the flow path connecting the liquid chamber L and the hose. Therefore, even when the piston 34 is in contact with the base portion 33a at the time of the last retreat, the pressure receiving area of the piston 34 that receives the pressure of the hydraulic oil increases. The recess 34a may be provided in the base 33a.

The natural length of the auxiliary spring 22 is obtained by subtracting the initial deflection (compression length) of the suspension spring 2 from the stroke length of the piston 34 (the distance that the piston 34 has moved from the maximum advanced state to the maximum retracted state). It is more than the length.

For example, in the shock absorber A, the state in which the initial load that gives the initial deflection X (mm) to the suspension spring 2 is applied to the suspension spring 2 with the piston 34 advanced to the maximum is optimal, and the stroke length of the piston 34 is set to Y ( mm). Considering the case where the auxiliary spring 22 is not provided, if the stroke length Y of the piston 34 does not exceed the initial deflection X of the suspension spring 2, the suspension spring 2 is idle even if the piston 34 is fully retracted in a no-load state. It does not become a state.

However, in the state where there is no auxiliary spring 22, the stroke length Y of the piston 34 is increased to increase the vehicle height adjustment amount without changing the conditions related to the suspension spring 2, such as the suspension spring 2 and the initial load applied to the suspension spring 2. In this case, when the stroke length Y exceeds the initial deflection X, the suspension spring 2 may be idle. This is because, when the piston 34 is retracted to the maximum in an unloaded state, the suspension spring is extended to X (mm) to reach a natural length, and then the piston 34 is further retracted by YX (mm). This is because the suspension spring 2 can move in the axial direction by X).

In contrast, in the shock absorber A, the natural length of the auxiliary spring 22 is longer than the length obtained by subtracting the initial deflection X from the stroke length Y of the piston 34, that is, (YX). Therefore, even if the vehicle height adjustment amount is increased without changing the suspension spring 2, the auxiliary spring 22 fills the gap of the amount that the suspension spring 2 can move in the axial direction (excessive retreat amount), and the suspension spring 2 is idle. To prevent it from entering a state.

Further, the contact height (the axial length in the most compressed state) of the auxiliary spring 22 is shorter than the axial length of the spacer 4, and the spring constant of the auxiliary spring 22 is much higher than the spring constant of the suspension spring 2. small. Therefore, in a state where the weight of the vehicle V stopped (still) on the horizontal ground is applied to the shock absorber A in the attached state, that is, in the 1G state, the auxiliary spring 22 is in the axial direction of the spacer 4 as shown in FIG. The spring holder 21 abuts against the tip of the spacer 4 and the approach to the piston 34 is restricted. Therefore, the compression of the auxiliary spring 22 is prevented by the spacer 4, and the spring receiver 21 is supported by the piston 34 through the auxiliary spring 22 and the spacer 4. FIG. 3 shows the shock absorber A in the 1G state. In FIG. 3, the piston 34 is advanced to the maximum on the right side of the center line, and the piston 34 is retracted to the maximum on the left side of the center line. . The close contact height of the auxiliary spring 22 is the axial length of the auxiliary spring 22 in the most compressed state. Specifically, in a state where adjacent coils (lines) constituting the auxiliary spring 22 are in contact with each other. This is the axial length of the auxiliary spring 22.

The suspension spring 2 does not reach the contact height even when the shock absorber A is in the most contracted state. That is, in the 1G state, as described above, the approach of the spring receiver 21 and the piston 34 is restricted by the spacer 4 and the compression of the auxiliary spring 22 is prevented, so that the spring constant of the spring member S is the same as that of the suspension spring 2. The spring constant is obtained, and the vehicle body B is substantially supported only by the suspension spring 2.

Hereinafter, the operation of the shock absorber A according to the present embodiment will be described.

When the vehicle V starts traveling, hydraulic oil is supplied to the liquid chamber L by the pump 31 and the piston 34 moves forward. As a result, the piston 34, the spring member S, the spring receiver 20, and the bracket 13 move downward in FIG. 3 with respect to the outer shell 10, so that the rod 11 retracts from the outer shell 10 and the shock absorber A extends. The car height goes up.

On the other hand, when the speed is lowered to stop the vehicle V, the hydraulic oil is discharged from the liquid chamber L by the pump 31 and the piston 34 moves backward. As a result, the piston 34, the spring member S, the spring receiver 20, and the bracket 13 move upward in FIG. 3 with respect to the outer shell 10, so that the rod 11 enters the outer shell 10 and the shock absorber A contracts. , Vehicle height decreases.

Further, during normal vehicle travel in which the vehicle weight, the passenger's weight, the load weight, etc. are applied to the shock absorber A, the auxiliary spring 22 is compressed and the spring receiver 21 comes into contact with the spacer 4. Compression is hindered. Therefore, during normal vehicle travel, the spring member S behaves so as to consist only of the suspension spring 2. However, when the shock absorber A is fully extended, such as when climbing over a level difference, even if the piston 34 is in the last retracted state, the auxiliary spring 22 is prevented from extending and the suspension spring 2 is prevented from playing. Further, since the vehicle weight is applied to the shock absorber A even when the vehicle V is stopped, the spring receiver 21 is kept in contact with the spacer 4.

Hereinafter, the function and effect of the shock absorber A according to the present embodiment will be described.

The spacer 4 has a cylindrical shape and is provided outside the auxiliary spring 22. According to this configuration, since the outer diameter of the spacer 4 can be increased, the pressure receiving area of the spacer 4 can be increased even if the spacer 4 is thin. The spacer 4 may be provided inside the auxiliary spring 22 and the shape of the spacer 4 can be changed as appropriate. For example, the spacer 4 may be plate-shaped or shaft-shaped.

Further, the spacer 4 is connected to the piston 34. According to the said structure, when the auxiliary spring 22 is extended more than the axial direction length of the spacer 4, it can prevent that the spacer 4 moves freely to an axial direction and the spacer 4 becomes idle. Even if the spacer 4 is connected to the spring receiver 21, the same effect can be obtained. However, when the spacer 4 connected to the spring receiver 21 is provided outside the auxiliary spring 22, it is preferable that the spacer 4 and the cylindrical portion 33 b always overlap each other, so that the cylindrical portion 33 b of the housing 33 is lengthened. There is a need to. This is because, when the spacer 4 shown in FIG. 3 is connected to the spring receiver 21 as it is, the piston 4 moves away from the housing 33 when the piston 34 moves forward as much as possible, and then the piston 34 moves backward. This is because it becomes difficult to insert the spacer 4 into the cylindrical portion 33 b of the housing 33.

The spacer 4 is seamlessly integrated with the piston 34, and the spacer 4 and the piston 34 are configured as one part. However, the spacer 4 and the piston 34 may be individually formed and then connected by fitting, screwing, bonding, or the like. That is, the state in which the spacer 4 and the piston 34 are connected may be such that the spacer 4 and the piston 34 are not separated from each other, and a part that functions as the spacer 4 and a part that functions as the piston 34 in one part. And the case where the spacer 4 and the piston 34 formed individually are physically or chemically joined, and the case where a joining member is interposed between the spacer 4 and the piston 34. Such a change is possible regardless of the arrangement and shape of the spacer 4.

Further, in the shock absorber A, the approach of the spring receiver 21 and the piston 34 is restricted by the spacer 4 in the mounted state of the stopped vehicle V. According to this configuration, during normal vehicle travel, the compression of the auxiliary spring 22 is prevented by the spacer 4, so that the vehicle body B is elastically supported by the suspension spring 2. Therefore, even if the auxiliary spring 22 is provided, the spring characteristic of the shock absorber A can be approximated to the spring characteristic of the shock absorber without the auxiliary spring. Further, the suspension spring 2 having a common specification can be used for the shock absorber A including the auxiliary spring 22 and the shock absorber without the auxiliary spring.

In addition, the said effect acquired by restrict | limiting the approach of the spring receiver 21 and the piston 34 with the spacer 4 is acquired also in the riding 1G state which added the rider's weight to the 1G state.

Hereinafter, the configuration, operation, and effect of the embodiment of the present invention will be described together.

The shock absorber A includes a shock absorber body 1, a spring receiver 21 that supports the upper end (one end) of the suspension spring 2 in FIG. 2 and is movable in the axial direction of the shock absorber body 1, and a housing that is attached to the shock absorber body 1. 33 and a jack 3 having a piston 34 movably provided on the housing 33 and forming a liquid chamber L between the housing 33 and an auxiliary spring 22 interposed between the spring receiver 21 and the piston 34. The spacer 4 is provided in parallel with the auxiliary spring 22 and has an axial length longer than the contact height of the auxiliary spring 22.

This configuration can prevent the suspension spring 2 from becoming idle even if the vehicle height adjustment amount is increased without changing the axial length of the suspension spring 2. Increasing the vehicle height adjustment amount can improve the foot-holding property when the vehicle is stopped. In addition, since the suspension spring 2 does not play with the auxiliary spring 22, the jack body 30 may drop or the jack body 30 and the flange may be connected to the jack body 30 even if the jack body 30 is supported by the elastic force of the suspension spring 2. It is possible to prevent the noise from being generated by repeating the separation and the contact with 14 and the jack body 30 and the flange 14 from being displaced.

In addition, according to the above configuration, even if the auxiliary spring 22 is provided, the spacer 4 can prevent the auxiliary spring 22 from having a close contact height. Therefore, since it can suppress that the coils which comprise the auxiliary spring 22 rub against each other and the coating of the auxiliary spring 22 peels off, it can suppress that an external appearance defect arises. Furthermore, since the auxiliary spring 22 does not reach the contact height, no load is applied to the auxiliary spring 22 when the coils constituting the auxiliary spring 22 are in contact with each other, and it is possible to prevent excessive stress from acting on the auxiliary spring 22. . Further, since the auxiliary spring 22 does not reach the contact height, the strength against compression in a state where the auxiliary spring 22 is at the contact height is unnecessary, so that the wire diameter of the auxiliary spring 22 can be reduced and the spring of the auxiliary spring 22 can be reduced. It becomes easy to reduce the constant.

In the shock absorber A, the approach of the spring receiver 21 and the piston 34 is restricted by the spacer 4 in a state where the shock absorber A is attached to the stopped vehicle V. According to this configuration, even if the auxiliary spring 22 is provided, the spring characteristic of the shock absorber A during vehicle travel can be approximated to the spring characteristic of the shock absorber without the auxiliary spring.

The spacer 4 is connected to the piston 34. According to this configuration, it is possible to prevent the spacer 4 from being idle.

The spacer 4 has a cylindrical shape and is provided outside the auxiliary spring 22. According to this configuration, even if the spacer 4 is thin, the pressure receiving area of the spacer can be increased.

Hereinafter, modifications of the above embodiment will be described.

In the shock absorber A, the suspension spring 2 and the auxiliary spring 22 are coil springs, but they may be square springs in which a material having a rectangular cross section is coiled.

In the shock absorber A, a guide 15 is provided on the outer periphery of the outer shell 10, and the spring receiver 21 and the piston 34 are in sliding contact with the guide 15. Instead of this, the outer periphery of the outer shell 10 may be a smooth surface, and the spring receiver 21 and the piston 34 may be in direct sliding contact with the outer periphery of the outer shell 10.

In the shock absorber A, the jack 3 includes a jack body 30 having a piston 34 and a housing 33, a pump 31 that supplies hydraulic oil to the jack body 30, and a motor 32 that drives the pump 31. However, the configuration of the jack 3 can be changed as appropriate. For example, the liquid used for the jack 3 may be other than hydraulic oil, and water, an aqueous solution, or the like may be used.

The shock absorber A is an inverted type in which the outer shell 10 is connected to the vehicle body B and the rod 11 is connected to the rear wheel W. Instead, an upright type in which the outer shell 10 is connected to the rear wheel W and the rod 11 is connected to the vehicle body B may be used.

Further, the shock absorber A is interposed between the vehicle body B and the rear wheel W of the motorcycle, but the shock absorber A may be mounted on a straddle-type vehicle other than the motorcycle, an automobile, or the like.

The above changes are possible regardless of the arrangement, shape, connection object, and method of the spacer 4, and the timing at which the spacer 4 restricts the proximity of the spring receiver 21 and the piston 34.

The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

This application claims priority based on Japanese Patent Application No. 2015-150255 filed with the Japan Patent Office on July 30, 2015 and Japanese Patent Application No. 2016-023212 filed with the Japan Patent Office on February 10, 2016 The entire contents of this application are hereby incorporated by reference.

Claims (4)

The shock absorber body,
A spring receiver that supports one end of the suspension spring and is movable in the axial direction of the shock absorber body;
A jack having a housing attached to the shock absorber main body, and a piston which is movably provided in the housing and forms a liquid chamber between the housing and the housing;
An auxiliary spring interposed between the spring receiver and the piston;
A spacer provided in parallel with the auxiliary spring, the axial length of which is longer than the contact height of the auxiliary spring;
Shock absorber. The shock absorber according to claim 1,
The shock absorber in which the approach of the spring receiver and the piston is restricted by the spacer in an attached state to a stopped vehicle. The shock absorber according to claim 1,
The spacer is a shock absorber connected to the piston. The shock absorber according to claim 1,
The spacer is a shock absorber provided in a cylindrical shape and provided outside the auxiliary spring.

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