JP7181748B2 - Front fork - Google Patents

Description

The present invention relates to improvements in front forks.

Conventionally, a front fork includes an outer tube with a bottom, an inner tube that is slidably inserted into the outer tube, a cylinder that stands on the bottom of the outer tube and moves in and out of the inner tube, and an inner tube. Some have a cylindrical case provided at the tip of the tube, and an annular lock piece that is attached to the outer periphery of the cylinder near the bottom of the outer tube and can move in and out of the case (for example, Patent Documents 1 and 2). .

As the inner tube intrudes into the outer tube, the cylinder intrudes into the inner tube, and when the case approaches the bottom of the outer tube, the lock piece is inserted into the case. As a result, a hydraulic lock chamber is formed between the lock piece and the outer tube between the tip of the case and the bottom of the outer tube, and the liquid is confined in the hydraulic lock chamber, increasing its internal pressure. and suppresses further intrusion of the inner tube into the outer tube.

The lock piece is movable in the axial direction of the cylinder, can be seated and removed from a valve seat provided at the bottom of the outer tube, and is biased toward the valve seat by a spring. When the inner tube moves away from the outer tube and the case moves away from the bottom, the lock piece is pulled up by the case. Then, the lock piece separates from the valve seat to open a passage formed between the lock piece and the cylinder, and the hydraulic lock chamber formed on the outer peripheral side of the lock piece communicates with the inside of the case through the passage.

As a result, the hydraulic lock state of the hydraulic lock chamber is released, and the liquid in the case flows through the passage toward the hydraulic lock chamber. In this way, when the lock piece is separated from the bottom, the spring is compressed, and when the lock piece is completely removed from the case, the elastic force of the spring returns the lock piece to the initial position where it is seated on the valve seat. Therefore, when the lock piece intrudes into the case again, the liquid can be confined in the hydraulic lock chamber to restore the hydraulic lock state.

JP-A-2000-310270 Japanese Patent Application Laid-Open No. 2006-17160

Here, in the front forks disclosed in Japanese Patent Application Laid-Open Nos. 2000-310270 and 2006-17160, the spring that urges the lock piece is a coil spring, and part or all of it is a spring between the lock piece and the cylinder. inserted in between. In this way, if the lock piece and the spring that urges it are arranged inside and outside, for example, in a front fork that uses an inner tube with a small inner diameter, the lock piece will also have a smaller diameter, so there will be less space to accommodate the spring. may not be guaranteed.

In addition, the lock piece of the conventional front fork described above functions as a check valve that opens the passage when the case is withdrawn. This can occur when a spring is provided to bias the lock piece.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a front fork that eliminates the above problems and that can be provided with a spring that biases the lock piece regardless of the inner tube inner diameter.

A front fork that solves the above problems consists of a cylindrical case provided at the tip of an inner tube that is slidably inserted into an outer tube, and a cylinder that is provided inside the outer tube and moves in and out of the inner tube. An annular lock piece that is mounted movably in the axial direction and that can move in and out of the case , a valve seat that is provided at the bottom that closes one end opening of the outer tube and on which the lock piece can be attached and detached, and a lock piece on the outer periphery of the cylinder. and a spring arranged in the axial direction to urge the lock piece toward the valve seat , and when the lock piece is inserted into the case and separated from the valve seat, the lock piece and the cylinder are separated from each other. A passage formed continuously over the entire axial length of the lock piece is opened, and the hydraulic lock chamber formed between the lock piece and the outer tube communicates with the inside of the case.

According to the above configuration, the spring that biases the lock piece is vertically aligned with the lock piece in the axial direction and is not inserted inside the lock piece. Therefore, even if the front fork adopts an inner tube with a small inner diameter and the lock piece has a small diameter, it is possible to secure a space for accommodating the spring.

Furthermore, according to the above configuration , when the lock piece advances in the case in the retracting direction, the lock piece moves away from the valve seat against the biasing force of the spring, thereby opening the passage and hydraulically locking the hydraulic lock chamber. state is released. Therefore, it is possible to prevent abnormal noise from being generated when the lock piece comes out of the case. Furthermore, when the lock piece is completely pulled out of the case, the lock piece can be seated on the valve seat by a spring and returned to the initial position where the passage is closed.

Further, in the front fork described above, a concave portion may be formed in the spring-side end portion of the lock piece. In this way, the recess creates a gap between the lock piece and the spring so that the spring end of this passageway is always kept open so that when the lock piece is withdrawn from the case, the hydraulic lock chamber is closed. can be reliably released from the hydraulic lock state.

Further, in the front fork, the spring may be an annular wave spring. In this way, the spring can be prevented from entering the inner peripheral side of the lock piece without interposing a washer or the like between the spring and the lock piece, and the lock piece and the spring are aligned in the axial direction. can be maintained.

According to the front fork of the present invention, the spring that biases the lock piece regardless of the inner tube inner diameter is provided.

1 is a longitudinal sectional view partially showing a front fork according to an embodiment of the invention; FIG. FIG. 2 is a longitudinal sectional view showing an enlarged part of FIG. 1; (a) is a plan view showing a lock piece of a front fork according to an embodiment of the present invention, (b) is an XX cross-sectional view of the lock piece of (a), and (c) is the lock piece of (a). It is a bottom view of. (a) is a front view showing a spring that biases a lock piece of a front fork according to an embodiment of the present invention, (b) is a plan view of the spring of (a), and (c) is a plan view of (a). Fig. 3 is a perspective view of a spring; FIG. 10 is a longitudinal sectional view showing a first modified example of the front fork according to the embodiment of the invention, showing an enlarged modified portion;

A front fork according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals throughout the several drawings indicate the same or corresponding parts. Also, the top and bottom when the front fork is attached to the vehicle are simply referred to as "top" and "bottom" unless otherwise specified.

A front fork F according to one embodiment of the present invention shown in FIG. 1 is a suspension device for suspending a front wheel in a straddle-type vehicle. A straddle-type vehicle is a general type of vehicle that is ridden in a posture astride a saddle, and includes motorcycles, scooters, bicycles, and the like. The front fork according to the present invention may be mounted on any straddle-type vehicle.

As shown in FIG. 1, a front fork F according to an embodiment of the present invention includes a telescopic tube member T having an outer tube 1 and an inner tube 2. As shown in FIG. Furthermore, the front fork F of this embodiment is of an upright type, and the inner tube 2 is slidably inserted from the upper end opening of the outer tube 1 .

A wheel-side bracket 10 is provided integrally with the outer tube 1 , and the outer tube 1 is connected to the axle of the front wheel via the wheel-side bracket 10 . On the other hand, the inner tube 2 is connected to the vehicle body via a vehicle body side bracket (not shown) connected to its upper end. In this manner, the front fork F is arranged with the outer tube 1 directed toward the front wheel (wheel) and the inner tube 2 directed toward the vehicle body, and is interposed between the vehicle body and the axle of the front wheel.

When the straddle-type vehicle runs on an uneven road surface and the front wheels vibrate vertically with respect to the vehicle body, the inner tube 2 moves in and out of the outer tube 1 and the tube member T expands and contracts. Such expansion and contraction of the tube member T is also called expansion and contraction of the front fork F.

Next, the upper end opening of the inner tube 2 is closed with a cap (not shown). On the other hand, the outer tube 1 has a cylindrical shape with a bottom, and the lower end opening of the outer tube 1 is closed with the bottom portion 1a. Further, the overlapping portion of the outer tube 1 and the inner tube 2 is closed by an oil seal 11 and a dust seal 12 . In this manner, the inside of the tube member T is a closed space, and the inside of the tube member T is filled with liquid and gas.

Further, a cylinder 3 is connected to the bottom portion 1a of the outer tube 1 with a bolt 30. As shown in FIG. The cylinder 3 includes a cylindrical cylinder body 3a and an annular valve case portion 3b projecting radially outward from the tip of the cylinder body 3a. The cylinder 3 is arranged with the cylinder main body 3a along the center of the outer tube 1 in the axial direction and the valve case portion 3b facing upward. inserted movably into the

A coil spring 4 as a suspension spring is laminated on the upper side of the valve case portion 3b of the cylinder 3. As shown in FIG. The upper end of this coil spring 4 is supported by a cap (not shown) that closes the upper end of the inner tube 2 . Therefore, it can be said that the coil spring 4 is interposed between the cylinder 3 and the inner tube 2 . Also, the coil spring 4 is a compression spring, and when compressed, it is elastically deformed and exerts an elastic force corresponding to the amount of deformation.

More specifically, since the cylinder 3 enters the inner tube 2 as the front fork F contracts, the more the front fork F contracts, the greater the amount of deformation of the coil spring 4 and the greater the generated elastic force. Become. The coil spring 4 urges the front fork F in the extension direction by its elastic force to elastically support the vehicle body. The suspension spring may be a spring other than the coil spring 4, such as an air spring.

Next, a reservoir chamber R is formed in the tube member T from the inner side of the cylinder main body 3a of the cylinder 3 to the upper side thereof, and a cylindrical reservoir chamber R is formed below the valve case portion 3b and on the outer peripheral side of the cylinder main body 3a. is formed. The liquid chamber L is partitioned into an upper expansion side chamber L1 and a lower pressure side chamber L2 by a piston portion 20 provided at the lower end of the inner tube 2 .

The expansion side chamber L1 and the compression side chamber L2 are each filled with liquid such as hydraulic oil. On the other hand, in the reservoir chamber R, the same liquid as the liquid in the growth side chamber L1 and the compression side chamber L2 is stored, and a gas such as air is enclosed above the liquid surface Rs of the liquid. The liquid surface Rs of the reservoir chamber R is set so as to always be positioned above the valve case portion 3b.

An annular first valve V1 that allows only the flow of liquid from the reservoir chamber R toward the expansion side chamber L1 is provided on the outer circumference of the valve case portion 3b, and the pressure side chamber L2 is provided on the inner circumference of the piston portion 20. There is provided an annular second valve V2 that allows only the flow of liquid from to the growth side chamber L1. Further, the upper portion of the cylinder body 3a is provided with a growth-side orifice O1 that opens into the expansion-side chamber L1, and the lower portion of the cylinder body 3a is provided with a compression-side orifice O2 that opens into the compression-side chamber L2. These expansion-side and compression-side orifices O1 and O2 function as resistance elements that provide resistance to the flow of liquid passing therethrough.

According to the above configuration, when the inner tube 2 is retracted from the outer tube 1 and the front fork F is extended, the piston portion 20 moves upward in the liquid chamber L to reduce the extension side chamber L1 and expand the compression side chamber L2. . At this time, the first and second valves V1 and V2 are closed, the liquid in the expansion side chamber L1 moves to the reservoir chamber R through the expansion side orifice O1, and the liquid in the reservoir chamber R passes through the compression side orifice O2. is supplied to the pressure-side chamber L2 that expands as the pressure increases.

During extension of the front fork F in this manner, the orifice O1 on the extension side provides resistance to the flow of the liquid from the extension side chamber L1 toward the reservoir chamber R. Therefore, when the front fork F extends, the pressure in the extension side chamber L1 increases, and a damping force on the extension side that suppresses the extension operation of the front fork F is generated.

Conversely, when the front fork F is contracted with the inner tube 2 entering the outer tube 1, the piston portion 20 moves downward in the fluid chamber L, the pressure side chamber L2 contracts, and the expansion side chamber L1 expands. At this time, the first and second valves V1 and V2 are opened, and liquid is supplied from both the reservoir chamber R and the compression side chamber L2 to the expanding expansion side chamber L1. Further, when the front fork F is contracted, the volume of the liquid chamber L is reduced by the volume of the inner tube 2 entering the liquid chamber L, resulting in an excess of liquid. is discharged from the pressure side chamber L2 to the reservoir chamber R.

During contraction of the front fork F in this manner, the orifice O2 on the compression side provides resistance to the flow of liquid from the compression side chamber L2 toward the reservoir chamber R. Therefore, when the front fork F contracts, the pressure in the compression side chamber L2 increases, and a compression side damping force that suppresses the contraction operation of the front fork F is generated.

Although the front fork F of this embodiment includes the first and second valves V1 and V2, the valve structure of the front fork can be changed as appropriate. For example, the second valve V2 may be closed to block communication between the growth side chamber L1 and the compression side chamber L2. Moreover, you may make it give resistance to the flow of the liquid which goes to the contraction side room L2 from the expansion side room L1, when the second valve V2 closes. Furthermore, a valve that opens and closes the upper end opening of the cylinder 3 may be provided to provide resistance to the upward flow of the liquid from the inside of the cylinder 3 .

Next, the extension spring 5 is laminated on the upper side of the piston portion 20 . The extension spring 5 is compressed between the piston portion 20 and the valve case portion 3b when the front fork F is fully extended, and absorbs the impact at the time of maximum extension. Although the extension spring 5 shown in FIG. 1 is a coil spring, it may be a spring other than the coil spring. Further, instead of the extension spring 5, a cushion rubber or the like may be provided, and this cushion rubber may reduce the shock when the front fork F is fully extended.

On the other hand, a tubular case 6 is provided at the lower end of the piston portion 20 . Further, an annular lock piece 7 is provided on the outer circumference of the lower end of the cylinder 3, and the lock piece 7 is inserted into the case 6 when the front fork F is most contracted. When the lock piece 7 is inserted into the case 6, the liquid between the lock piece 7 and the outer tube 1 is confined to enter a hydraulically locked state. Mitigates the shock at the time of maximum contraction.

More specifically, as shown in FIG. 2, the lock piece 7 is attached to the outer periphery of the lower end portion of the cylinder 3 so as to be axially movable, and is separated from the valve seat 1b provided on the bottom portion 1a of the outer tube 1. It is possible to sit down. Further, the lock piece 7 is biased toward the valve seat 1b (in the seating direction) by a spring 8 laminated on its upper side.

In addition, the upper end of the lock piece 7 is formed with a concave portion 7a which is recessed one step lower than the other portions. The number and arrangement of the recesses 7a can be changed as appropriate, but in this embodiment, the recesses 7a are formed at two locations in the upper end of the lock piece 7 in the circumferential direction, as shown in FIG. 3(a). there is As shown in FIGS. 3(a) and 3(b), the inner periphery of the lock piece 7 is formed with a longitudinal groove 7b extending in the axial direction, which is continuous with the recess 7a. The number of vertical grooves 7b can also be changed as appropriate, but in this embodiment, they are formed at four locations in the circumferential direction.

Furthermore, as shown in FIGS. 3(b) and 3(c), the lower end of the lock piece 7 is provided with a flange portion 7c projecting radially outward, and the outer peripheral edge of the flange portion 7c projects downward. An annular leg portion 7d is provided. Then, as shown in FIG. 2, the leg portion 7d is adapted to be seated on and off the valve seat 1b. Further, as shown in FIG. 2, when the lock piece 7 is attached to the outer circumference of the cylinder 3, a gap is formed between them which continues in the axial direction of the lock piece 7, and this gap forms a liquid passage P. be done.

Next, as shown in FIG. 4, the spring 8 stacked on the lock piece 7 is an annular wave spring curved so that a part of the annular plate material in the circumferential direction is high and the other part is low. When force is applied in the axial direction, it is compressed and exhibits elastic force. Specifically, a known wave washer or the like can be used as the wave spring. Assuming that the highly raised portion of the spring 8 is the protruding portion 8a and the low sunken portion is the depressed portion 8b, the number of the protruded portions 8a and the depressed portions 8b can be changed as appropriate. As shown in (c), two raised portions 8a and two depressed portions 8b appear alternately in the circumferential direction.

As shown in FIG. 2, the depressed portion 8b of the spring 8 abuts the upper end of the lock piece 7, and the raised portion 8a abuts a washer 9 mounted on the outer periphery of the cylinder 3. abut against a step 3c formed on the outer periphery of the . Thus, the spring 8 and the lock piece 7 are arranged side by side in the axial direction, and the spring 8 is interposed between the cylinder 3 and the lock piece 7 to urge the lock piece 7 downward, that is, in the seating direction. do.

According to the above configuration, before the lock piece 7 is inserted into the case 6, the spring 8 keeps the lock piece 7 seated on the valve seat 1b. Then, when the amount of contraction of the front fork F increases and the piston portion 20 approaches the bottom portion 1a, and the lock piece 7 is inserted into the case 6, the lock piece 7 is pushed between the tip of the case 6 and the bottom portion 1a. A hydraulic lock chamber Q is formed between and the outer tube 1, and the liquid is confined in the hydraulic lock chamber Q, resulting in a hydraulic locked state. As a result, the pressure in the hydraulic lock chamber Q rises, the pressure suppresses the approach of the piston portion 20 to the bottom portion 1a, and the retracting operation of the front fork F stops.

Further, when the front fork F is switched from the most contracted state to the extended operation in this way and the lock piece 7 is withdrawn from the case 6 as the piston portion 20 moves away from the bottom portion 1a, the biasing force of the spring 8 is applied. The lock piece 7 is pulled up by the case 6 against it. Then, the lock piece 7 is separated from the valve seat 1b, and the liquid inside the case 6 flows into the passage P through the gap formed between the upper end of the lock piece 7 and the spring 8. It goes to the hydraulic lock chamber Q through the gap formed between 7d and the valve seat 1b.

Thus, when the operating direction of the front fork F is switched to the extension operation and the lock piece 7 is withdrawn from the case 6, the passage P is opened and the hydraulically locked state of the hydraulically lock chamber Q is released. As a result, the lock piece 7 can be quickly withdrawn from the case 6, and abnormal noise generated when the lock piece 7 is withdrawn from the case 6 due to the depressurization of the hydraulic lock chamber Q can be prevented.

Furthermore, when the lock piece 7 is completely removed from the case 6, the biasing force of the spring 8 returns the lock piece 7 to the initial position where it is seated on the valve seat 1b. When the lock piece 7 is in such an initial position, the passage P is closed. Therefore, when the amount of contraction of the front fork F increases again and the lock piece 7 is inserted into the case 6, the liquid is again confined in the hydraulic lock chamber Q, resulting in a hydraulic locked state.

The operational effects of the front fork F according to the embodiment of the invention will be described below.

The front fork F according to this embodiment includes an outer tube 1, an inner tube 2 slidably inserted into the outer tube 1, and a cylinder 3 provided inside the outer tube 1 and entering and exiting the inner tube 2. , a cylindrical case 6 provided at the lower end (tip) of the inner tube 2, and an annular lock piece 7 mounted on the outer circumference of the cylinder 3 so as to be axially movable and capable of moving in and out of the case 6. , and a spring 8 arranged axially side by side with the lock piece 7 on the outer circumference of the cylinder 3 and biasing the lock piece 7 .

According to the above configuration, when the front fork F is contracted and the lock piece 7 is inserted into the case 6, the liquid is confined on the outer peripheral side of the lock piece 7 to enter a hydraulically locked state, and the hydraulically locked effect is achieved. can mitigate the shock when the front fork F is most contracted. Furthermore, since the lock piece 7 is urged by the spring 8, even if the lock piece 7 deviates from the initial position, the spring 8 can return the lock piece 7 to the initial position.

Furthermore, in the present embodiment, the spring 8 that biases the lock piece 7 is vertically aligned with the lock piece 7 in the axial direction so that it is not inserted inside the lock piece 7 . Therefore, for example, even if the lock piece 7 has a small diameter in the front fork F that employs the inner tube 2 with a small inner diameter, a space for accommodating the spring 8 can be secured. That is, according to the above configuration, the spring 8 that biases the lock piece 7 regardless of the inner tube inner diameter is provided.

Further, in the front fork F of the present embodiment, a valve seat 1b on which the lock piece 7 can be seated and removed is provided on the bottom portion 1a that closes the lower end opening (one end opening) of the outer tube 1. As shown in FIG. A spring 8 biases the lock piece 7 toward the valve seat 1b. Further, when the lock piece 7 is removed from the valve seat 1b while being inserted into the case 6, the passage P formed between the lock piece 7 and the cylinder 3 is opened, and the lock piece 7 and the outer tube 1 are connected. A passage P communicates between the hydraulic lock chamber Q formed therebetween and the inside of the case 6 .

According to the above configuration, when the lock piece 7 advances in the case 6 in the withdrawal direction, the lock piece 7 resists the biasing force of the spring 8 and leaves the valve seat 1b. As a result, the passage P is opened and the hydraulic lock state is released, so that when the lock piece 7 comes out of the case 6, abnormal noise can be prevented. Furthermore, when the lock piece 7 is completely pulled out of the case 6, the spring 8 causes the lock piece 7 to be seated on the valve seat 1b so that the passage P can be returned to the initial closed position.

Further, in the front fork F of the present embodiment, a concave portion 7a is formed at the upper end of the lock piece 7 (the end on the spring 8 side). Therefore, even when the lock piece 7 and the spring 8 that biases it are arranged side by side in the axial direction, a gap is formed between the lock piece 7 and the spring 8 by the recess 7a. The gap allows the upper end of the passage P to be kept open at all times. Therefore, when the lock piece 7 withdraws from the case 6, the hydraulic lock state can be reliably released.

Furthermore, in the front fork F of the present embodiment, a vertical groove 7b is formed along the axial direction on the inner peripheral side of the lock piece 7 so as to continue to the recess 7a. Therefore, it is easy to secure the flow area of the passage P.

Further, in the front fork F of the present embodiment, the spring 8 that biases the lock piece 7 is an annular wave spring. Therefore, even when the upper end of the lock piece 7 and the spring 8 are brought into direct contact with each other as in the present embodiment, the spring 8 can be prevented from entering the inner peripheral side of the lock piece 7 . In other words, according to the above configuration, even if the spring 8 that urges the lock piece 7 is brought into direct contact with the upper end of the lock piece 7, they can be maintained in a state of being arranged side by side in the axial direction.

Further, the front fork F of this embodiment includes a washer 9 that supports the upper end of the spring 8 (the end opposite to the lock piece 7), and this washer 9 hits a step 3c formed on the outer circumference of the cylinder 3. It's like Thus, in this embodiment, one end of the spring 8 is supported by the cylinder 3 via the washer 9, and the spring 8 can easily bias the lock piece 7. As shown in FIG.

Furthermore, according to the above configuration, compared to the case where a snap ring is attached to the outer periphery of the cylinder 3 and the washer 9 is abutted against the snap ring, the snap ring can be omitted, and the number of parts can be reduced. Moreover, since the spring 8 is abutted against the washer 9, the radial length of the step 3c can be shortened, and the thickness of the cylinder 3 can be reduced. However, the washer 9 may be supported by a snap ring attached to the outer circumference of the cylinder 3, or the washer 9 may be eliminated and the spring 8 may be directly abutted against the step 3c of the cylinder 3.

Moreover, the spring 8 is not limited to a wave spring, and may be a spring other than this. For example, the spring 8 may be a disk spring, coil spring, spring washer, or the like. FIG. 5 shows an example in which the spring 8A for biasing the lock piece 7 is changed to a coil spring.

As shown in FIG. 5, when the spring 8A for urging the lock piece 7 is a coil spring, a cylindrical guide 80 is provided on the outer periphery of the spring 8A, and a washer 9A abutting on the upper end of the spring 8A It is preferable to provide a pawl 9a projecting radially outward and to insert the pawl 9a into a notch 80a formed in the guide 80. As shown in FIG. By doing so, the radial deviation of the guide 80 with respect to the washer 9A can be suppressed, and the radial deviation of the washer 9A with respect to the cylinder 3 can be suppressed. As a result, the guide 80 prevents the spring 8A from deviating from the cylinder 3 in the radial direction, thereby preventing the spring 8A from coming off the lock piece 7. As shown in FIG.

Furthermore, as shown in FIG. 5, when the spring 8A for biasing the lock piece 7 is a coil spring, it is preferable to interpose a washer 81 between the spring 8A and the lock piece 7. As shown in FIG. By doing so, it is possible to reliably prevent the spring 8A from entering the lock piece 7 on the inner peripheral side. That is, the lock piece 7 and 8A that urges it do not have to be in direct contact, and such a change is possible regardless of the type of spring that urges the lock piece 7.

Furthermore, as shown in FIG. 5, even when a washer 81 is interposed between the lock piece 7 and the spring 8A, a concave portion 7a is formed in the upper end of the lock piece 7 (the end on the side of the spring 8A). Good. With this configuration, a gap is formed by the recess 7a between the lock piece 7 and the washer 81, so that the upper end of the passage P can always be kept open by the gap. However, the lock piece 7 does not necessarily have to function as a check valve for opening and closing the passage P, and such a change is possible regardless of the type of spring that urges the lock piece 7 .

Although preferred embodiments of the invention have been described in detail above, modifications, variations, and changes are possible without departing from the scope of the claims.

F... front fork, P... passage, Q... hydraulic lock chamber, 1... outer tube, 1a... bottom, 1b... valve seat, 2... inner tube, 3 ... cylinder, 6 ... case, 7 ... lock piece, 7a ... recessed part, 8, 8A ... spring

Claims (3)

an outer tube;
an inner tube slidably inserted into the outer tube;
a cylinder that is provided in the outer tube and moves in and out of the inner tube;
a cylindrical case provided at the tip of the inner tube;
an annular lock piece attached to the outer periphery of the cylinder so as to be axially movable and capable of moving in and out of the case;
a valve seat provided at a bottom portion that closes one end opening of the outer tube and on which the lock piece can be seated and removed;
a spring arranged axially with the lock piece on the outer circumference of the cylinder and biasing the lock piece toward the valve seat ;
When the lock piece is inserted into the case and is separated from the valve seat, a passage continuously formed between the lock piece and the cylinder along the entire axial length of the lock piece opens. A hydraulic lock chamber formed between the lock piece and the outer tube communicates with the inside of the case through the passage.
A front fork characterized by: 2. The front fork according to claim 1 , wherein a concave portion is formed in the spring-side end of the lock piece. The front fork according to claim 1 or 2 , wherein the spring is an annular wave spring.

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