JP6397726B2 - Cylinder device and cover member - Google Patents

Description

  The present invention relates to a cylinder device and a cover member.

  For example, in a strut-type shock absorber described in Patent Document 1, a dust boot as a cover member is held by a bump cap with a convex portion on the inner periphery being locked to a flange portion provided on the outer periphery of the bump cap.

  The dust boot is provided with a thin skirt portion at the end, and a convex portion that is engaged with the flange portion of the bump cap on the inner periphery thereof. For this reason, when the dust boot is fitted on the bump cap and pressed against the flange portion, the skirt portion is elastically deformed to increase the diameter, and after the convex portion has passed over the flange portion, the skirt portion is reduced in diameter. Thereby, the convex part of a dust boot is latched by the flange part of a bump cap. As described above, the dust boot can be easily assembled to the bump cap as the skirt portion is deformed.

JP 2003-65381 A

  However, in the strut type shock absorber, the dust boot may not be assembled to the bump cap unless the coil spring and the mount member are assembled to the cylinder.

  In this case, since the operator puts a finger through the gap of the coil spring and presses the dust boot against the bump cap only with the force of the fingertip, it is difficult to assemble the dust boot onto the bump cap even with the above technique.

  This invention is made | formed in view of such a technical subject, and aims at improving the assembly | attachment property of a cover member.

1st invention is a cylinder device, Comprising: The cover member which has a cylinder, the expandable bellows part, and the small diameter part whose inner diameter is smaller than the internal diameter of a bellows part, The small diameter part of the cover member fitted by the cylinder There comprises a cap member which projections provided on the outer periphery to be engaged, and the small diameter portion of the cover member is bulging portion bulging radially outward is formed, swollen portion, the radial portion and the peripheral The thickness of the radial direction portion is smaller than the thickness of the circumferential direction portion .

  In the first invention, when the cover member is assembled to the cap member, the bulging portion is elastically deformed in the circumferential direction of the small diameter portion. For this reason, the small-diameter portion is expanded in diameter in a state where the peripheral length is extended. According to this, even if the force pressing the cover member against the cap member is small, the small diameter portion of the cover member can easily get over the convex portion of the cap member.

2nd invention is a cover member, Comprising: The bellows part which can be expanded-contracted, The small diameter part whose inner diameter is smaller than the internal diameter of the bellows part latched by the convex part provided in the outer periphery of a to-be-protected body, A small diameter part It possesses a bulging portion, a bulging radially outward formed, swollen portion, and a radial portion and the circumferential portion, the thickness of the radial portion, than the plate thickness of the circumferential portion Is also thin .

In the second invention, when the cover member is assembled to the protected body, the bulging portion is elastically deformed in the circumferential direction of the small diameter portion. For this reason, the small-diameter portion is expanded in diameter in a state where the peripheral length is extended. According to this, even if the force which presses a cover member to a to-be-protected body is small, the small diameter part of a cover member can easily get over the convex part of a to-be-protected body.
3rd invention is a cylinder apparatus, Comprising: It has a cylinder from which a piston rod extends from one end, A bellows part which can be expanded and contracted, and a small diameter part whose inner diameter is smaller than the inner diameter of a bellows part, and protects a piston rod A cylindrical cover member, and a cap member fitted on the cylinder and provided with a convex portion on the outer periphery for locking the small diameter portion of the cover member. A bulging portion that swells is formed, and a flat portion that extends in a hook shape radially outward and engages with a convex portion of the cap member is formed at the proximal end of the small diameter portion of the cover member. It is provided in the excluded range.
4th invention is a cover member, Comprising: The bellows part which can be expanded-contracted, the small diameter part whose inner diameter is smaller than the internal diameter of the bellows part latched by the convex part provided in the outer periphery of the to-be-protected body, And a bulging portion that bulges outward in the radial direction, and is extended to the proximal end side of the small diameter portion in a hook shape and locked to the convex portion of the protected body. The flat portion is provided in a range excluding the bulging portion.

  According to the present invention, the assembling property of the cover member can be improved.

It is a fragmentary sectional view of the shock absorber which concerns on embodiment of this invention. It is sectional drawing in the convex part of a bump cap. It is the figure which looked at the dust boot from the small diameter part side. It is a figure for demonstrating the bulging part of a dust boot.

  Hereinafter, a shock absorber 100 according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  A shock absorber 100 as a cylinder device is attached to an automobile (not shown), positions a wheel (not shown) and generates a damping force to suppress vibration of a vehicle body (not shown). It is.

  As shown in FIG. 1, the shock absorber 100 includes a cylinder 1 in which a piston rod 1 a extends from one end, a mount member 2 connected to the end of the piston rod 1 a, and a spring seat 3 provided on the outer periphery of the cylinder 1. And a coil spring 4 interposed between the mount member 2 and the spring seat 3, a bump stopper 5 fitted to the piston rod 1 a, and a piston rod 1 a side end of the cylinder 1. A bump cap 6 as a cap member and a dust boot 7 as a cylindrical cover member for protecting the piston rod 1a are provided.

  At the end of the cylinder 1 opposite to the piston rod 1a, a bracket 1b for connecting the shock absorber 100 and a hub carrier (not shown) for holding wheels is provided. The shock absorber 100 is connected to the vehicle body by the mount member 2 and is connected to the hub carrier by the bracket 1b and assembled to the vehicle.

  The coil spring 4 is sandwiched between the mount member 2 and the spring seat 3 in a compressed state, and biases the cylinder 1 and the mount member 2 away from each other. An annular rubber sheet 8 is interposed between the mount member 2 and the coil spring 4 so that the mount member 2 and the coil spring 4 do not directly contact each other.

  The bump stopper 5 is formed of rubber, urethane, or the like, and contacts the top surface of the bump cap 6 when the shock absorber 100 is contracted to the most contracted length, and restricts the stroke of the shock absorber 100 on the contraction side.

  The bump cap 6 is made of a resin, and includes a convex portion 6a provided at three locations in the circumferential direction equally on the outer peripheral surface and a flange portion 6b provided on the outer peripheral side of the opening end.

  The shape of the convex portion 6a is a triangle having a vertex on the flange portion 6b side, as shown in FIG. Further, the end surface 6 c on the flange portion 6 b side of the convex portion 6 a is a flat portion orthogonal to the axial direction of the shock absorber 100. The convex portion 6a will be described later.

  In the present embodiment, as shown in FIG. 1, the flange portion 6b is partially provided so that the convex portion 6a and the flange portion 6b do not overlap in the axial direction. This considers the mold division for manufacturing the bump cap 6 by injection molding.

  The dust boot 7 is made of resin, and as shown in FIG. 1, the expandable bellows portion 7a, the small diameter portion 7b having an inner diameter smaller than the inner diameter of the bellows portion 7a formed at one end, and the outer periphery of the other end And a flange portion 7c formed on the side.

  As shown in FIGS. 1 and 3, the small diameter portion 7b is formed with a bulging portion 7d that bulges radially outward. In this embodiment, the bulging part 7d is formed in eight places. As shown in FIG. 2 and FIG. 3, a flat portion 7e extending in the shape of a flange outward in the radial direction is provided in a range excluding the bulging portion 7d at the proximal end of the small diameter portion 7b. The bulging portion 7d and the flat portion 7e will be described later.

  In the present embodiment, as shown in FIG. 3, there are two types of shapes of the bulging portion 7 d of the dust boot 7. This takes into account the mold division for manufacturing the dust boot 7 by blow molding.

  Moreover, as shown in FIG. 3, the dust boot 7 is manufactured by blow molding, so that the plate thickness t1 of the radial portion 7f in the bulging portion 7d is thinner than the plate thickness t2 of the circumferential portion 7g. This will be described later.

  As shown in FIG. 1, in the dust boot 7, the flange portion 7c is sandwiched between the mount member 2 and the rubber sheet 8, and the small diameter portion 7b is held between the convex portion 6a of the bump cap 6 and the flange portion 6b. And assembled to the shock absorber 100.

  Therefore, when the dust boot 7 is extended beyond its free length, the small diameter portion 7b is locked to the convex portion 6a of the bump cap 6, and when the dust boot 7 is contracted from its free length, the small diameter portion 7b. Is locked to the flange portion 6 b of the bump cap 6.

  In a state where the small diameter portion 7b of the dust boot 7 is locked to the convex portion 6a of the bump cap 6, as shown in FIG. 2, the flat portion 7e of the dust boot 7 and the end face 6c of the convex portion 6a of the bump cap 6 Abut. As described above, since the end surface 6c of the convex portion 6a is flat, the flat portion 7e of the dust boot 7 is in surface contact with the end surface 6c of the convex portion 6a.

  According to this, when the shock absorber 100 is operated and the dust boot 7 is extended, the surface pressure that the dust boot 7 receives from the convex portion 6a of the bump cap 6 can be reduced. Therefore, the strength and durability of the dust boot 7 can be improved, and the dust boot 7 can be prevented from being detached from the bump cap 6.

  When the dust boot 7 is assembled to the bump cap 6, the dust boot 7 is fitted to the bump cap 6 and the small diameter portion 7b is pressed against the convex portion 6a. As described above, since the convex portion 6a is a triangle having an apex on the flange portion 6b side, the force pressing the dust boot 7 acts as a force for expanding the small diameter portion 7b. For this reason, as shown by the arrow in FIG. 4, the small-diameter portion 7b is expanded in diameter in a state where the peripheral length is increased by elastic deformation of the bulging portion 7d so as to extend in the circumferential direction of the small-diameter portion 7b.

  As described above, the dust boot 7 is manufactured by blow molding, whereby the thickness t1 of the radial portion 7f in the bulging portion 7d can be made thinner than the thickness t2 of the circumferential portion 7g. According to this, since the radial portion 7f is easily deformed in the circumferential direction, when the dust boot 7 is assembled to the bump cap 6, the small diameter portion 7b of the dust boot 7 is greatly expanded.

  Thereby, the small diameter part 7b gets over the convex part 6a of the bump cap 6, and when the shape of the bulging part 6d is restored by an elastic force thereafter, the diameter is reduced and locked to the convex part 6a.

  Thus, when the dust boot 7 is assembled to the bump cap 6, the bulging portion 7d is elastically deformed in the circumferential direction of the small diameter portion 7b. For this reason, the small diameter portion 7b is expanded in diameter in a state in which the peripheral length is extended. According to this, even if the force pressing the dust boot 7 against the bump cap 6 is small, the small diameter portion 7b of the dust boot 7 can easily get over the convex portion 6a of the bump cap 6. Therefore, the assembling property of the dust boot 7 can be improved.

  Further, in the present embodiment, as described above, the convex portions 6a of the bump cap 6 are provided at three portions equally in the circumferential direction. In this way, by providing the projection 6 a by dividing it into a plurality in the circumferential direction, the small diameter portion 7 b of the dust boot 7 is only partially enlarged at the position of the projection 6 a of the bump cap 6. It is possible to get over the convex portion 6a.

  According to this, even if the force which presses the dust boot 7 against the bump cap 6 is small as compared with the case where the convex portions 6 a of the bump cap 6 are continuously provided on the entire circumference, the dust boot 7 is attached to the bump cap 6. Can be assembled.

  In addition, in the strut type shock absorber, the dust boot may not be assembled to the bump cap unless the coil spring and the mount member are assembled to the cylinder. In this case, the operator inserts a finger through the gap of the coil spring, and the dust boot is assembled to the bump cap only with the force of the fingertip.

  On the other hand, according to the present embodiment, the dust boot 7 can be assembled to the bump cap 6 even if the force for pressing the dust boot 7 against the bump cap 6 is small. Even after 2 is assembled, the dust boot 7 can be easily assembled to the bump cap 6.

  As described above, according to the present embodiment, when the dust boot 7 is assembled to the bump cap 6, the bulging portion 7d is elastically deformed in the circumferential direction of the small diameter portion 7b. For this reason, the small diameter portion 7b is expanded in diameter in a state in which the peripheral length is extended. According to this, even if the force pressing the dust boot 7 against the bump cap 6 is small, the small diameter portion 7b of the dust boot 7 can easily get over the convex portion 6a of the bump cap 6. Therefore, the assembling property of the dust boot 7 can be improved.

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

  The shock absorber 100 includes a cylinder 1 from which a piston rod 1a extends from one end, a telescopic bellows portion 7a, and a small-diameter portion 7b whose inner diameter is smaller than the inner diameter of the bellows portion 7a, and a cylinder that protects the piston rod 1a. A dust cap 7 and a bump cap 6 fitted on the cylinder 1 and provided with a convex portion 6a on the outer periphery to which the small diameter portion 7b of the dust boot 7 is locked, and the small diameter portion 7b of the dust boot 7 Is characterized in that a bulging portion 7d bulging radially outward is formed.

  The dust boot 7 includes a cylindrical bellows portion 7a that can be expanded and contracted, a small diameter portion 7b that has an inner diameter smaller than the inner diameter of the bellows portion 7a that is locked to the convex portion 6a provided on the outer periphery of the bump cap 6, And a bulging portion 7d bulging outward in the radial direction formed in the small diameter portion 7b.

  In these configurations, when the dust boot 7 is assembled to the bump cap 6, the bulging portion 7d is elastically deformed in the circumferential direction of the small diameter portion 7b. For this reason, the small diameter portion 7b is expanded in diameter in a state in which the peripheral length is extended. According to this, even if the force pressing the dust boot 7 against the bump cap 6 is small, the small diameter portion 7b of the dust boot 7 can easily get over the convex portion 6a of the bump cap 6. Therefore, the assembling property of the dust boot 7 can be improved.

  As mentioned above, although embodiment of this invention was described, the said embodiment is only what showed a part of application example of this invention, and in the meaning which limits the technical scope of this invention to the specific example of said embodiment. Absent.

  For example, in the above-described embodiment, the cylinder device is described as a shock absorber 100 for an automobile. However, the cylinder device is for a two-wheeled vehicle, a railway vehicle, a house, a household appliance, an industrial machine, a shipping electrical device, and the like. It may be. The cylinder device may be an actuator or the like, for example.

  In the above embodiment, the cover member is described as the dust cover 7 of the shock absorber 100. However, the cover member is, for example, each part of a motorcycle, a railway vehicle, a house, a home appliance, an industrial machine, a shipping electrical device, or the like. It can also be used as a dust cover. In addition to the dust cover, a harness cover, a hose cover, or the like can be used.

  Moreover, in the said embodiment, although the dust boot 7 is made from resin, as long as the bulging part 7d can be elastically deformed to the circumferential direction of the small diameter part 7b, you may use materials other than resin. Accordingly, various materials such as rubber, spring steel, and cloth can be used as the material of the dust boot 7.

  In the above embodiment, the shock absorber 100 is described as a strut type shock absorber. However, a shock absorber other than a strut type may be used, for example, a shock absorber in which a coil spring is disposed separately.

  Moreover, in the said embodiment, although the convex part 6a of the bump cap 6 is provided in the circumferential direction equally divided three places in the outer peripheral surface of the bump cap 6, the number of the convex parts 6a may be two or less. And four or more. Moreover, the arrangement | positioning in the circumferential direction of the convex part 6a does not need to be equally divided.

  Moreover, in the said embodiment, although the bulging part 7d of the dust boot 7 is provided in eight places, the number of the bulging parts 7d may be seven or less, and may be nine or more. Good.

DESCRIPTION OF SYMBOLS 100 ... Shock absorber (cylinder apparatus), 1 ... Cylinder, 1a ... Piston rod, 6 ... Bump cap (cap member), 6a ... Convex part, 7 ... Dust boot (cover) Member), 7a ... bellows part, 7b ... small diameter part, 7d ... bulge part

Claims (4)

A cylinder with a piston rod extending from one end;
A cylindrical cover member that has an expandable bellows portion and a small diameter portion having an inner diameter smaller than the inner diameter of the bellows portion, and protects the piston rod;
A cap member fitted on the cylinder and provided with a convex portion on the outer periphery to which the small diameter portion of the cover member is locked;
With
The small diameter portion of the cover member is formed with a bulging portion that bulges radially outward ,
The bulging portion has a radial portion and a circumferential portion,
The plate thickness of the radial portion is thinner than the plate thickness of the circumferential portion,
A cylinder device characterized by that. Stretchable bellows,
A small-diameter portion whose inner diameter is smaller than the inner diameter of the bellows portion locked to a convex portion provided on the outer periphery of the protected body;
A bulging portion swelled radially outward formed in the small diameter portion;
I have a,
The bulging portion has a radial portion and a circumferential portion,
The plate thickness of the radial portion is thinner than the plate thickness of the circumferential portion,
The cover member characterized by the above-mentioned. A cylinder with a piston rod extending from one end;
A cylindrical cover member that has an expandable bellows portion and a small diameter portion having an inner diameter smaller than the inner diameter of the bellows portion, and protects the piston rod;
A cap member fitted on the cylinder and provided with a convex portion on the outer periphery to which the small diameter portion of the cover member is locked;
With
The small diameter portion of the cover member is formed with a bulging portion that bulges radially outward,
A flat portion extending radially outward in a hook shape and locked to the convex portion of the cap member at a base end side end of the small diameter portion of the cover member is a range excluding the bulging portion. Provided in the
A cylinder device characterized by that. Stretchable bellows,
A small-diameter portion whose inner diameter is smaller than the inner diameter of the bellows portion locked to a convex portion provided on the outer periphery of the protected body;
A bulging portion swelled radially outward formed in the small diameter portion;
Have
  A flat portion extending in a radial shape on the proximal end side of the small-diameter portion and hooked to the convex portion of the protected body is provided in a range excluding the bulging portion. ,
The cover member characterized by the above-mentioned.

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