JP3159227U - Hydraulic cylinder - Google Patents

Abstract

Disclosed is a hydraulic cylinder that prevents damage and seizure of a convex / concave portion and has a large impact relaxation effect. A cylinder with a cover at both ends, an operating shaft that penetrates one side cover and has a piston at the tip and reciprocates the cylinder, and can be fitted to the piston end surface or cover end surface opposite to the operating shaft side A concave or convex portion is provided, and a cushion mechanism is provided by fitting the concave and convex portions. The member provided with the concave portion or the convex portion is constituted by a member separate from the cover or the piston, and the member provided with the concave portion or the convex portion is freely movable in the direction perpendicular to the axis and in the axial direction with respect to the axis of the piston or the cover. [Selection] Figure 1

Description

  The present invention relates to a hydraulic cylinder provided with a cushion mechanism that decelerates the moving speed of a piston at the stroke end of the hydraulic cylinder.

  Conventionally, as a method of reducing the impact at the stroke end of the cylinder due to the inertia of the moving object attached to either the cylinder member or the piston member, a shaft is attached to the bottom end of the piston member that moves the hydraulic cylinder in the axial direction. A concave plunger chamber is provided in the direction, and the cushion plunger is inserted so as to be movable back and forth in the axial direction, and inserted in the cylinder bottom corresponding to the hydraulic fluid chamber of the cylinder in an axial direction slightly larger in diameter than the shaft diameter of the cushion plunger. A hole is provided, and a seat portion on which the tip end portion of the cushion plunger that has entered the insertion hole is seated is provided between the passage continuing in the axial direction of the insertion hole, and the plunger chamber and the hydraulic fluid chamber are provided. A passage that communicates with each other via a small-diameter communication hole and that passes through the longitudinal direction of the cushion plunger. Method of alleviating the impact of the moving end of the piston is employed by providing an orifice (see Patent Document 1).

  Further, as shown in FIG. 6, an airtight sliding piston 45 fixed to an operating shaft 44 that reciprocates a cylinder (cylindrical body) 43 having a head cover 41 and a rod cover 42 at both ends is provided. A convex portion 46 in the axial direction is provided on the end surface of the piston 45 corresponding to the hydraulic fluid chamber K constituted by the above, and the convex portion 46 is fitted to the end surface of the head cover 41 corresponding to the opposing hydraulic fluid chamber K. A method of providing the recess 47 is employed. That is, by fitting the convex portion 46 to the concave portion 47, the pressure of the hydraulic fluid chamber K is increased by the narrowing effect of the gap between the convex portion 46 and the concave portion 47, and the moving speed of the piston 45 is decelerated, and the impact at the stroke end. It is a method to relieve.

Japanese Utility Model Publication No. 63-112602

  In the conventional hydraulic cylinder cushion mechanism described in detail above, a method of reducing the gap between the convex portion in the axial direction provided on the piston and the concave portion opposed to the piston is used in order to increase the impact mitigating effect by the cushion. Yes. However, if the gap is reduced, damage may occur if the outer periphery of the convex portion interferes with the inlet portion of the concave portion due to the misalignment between the concave portion and the convex portion, or the contact portion seizes due to forcible fitting. Further, if the gap is increased, the impact mitigating effect is reduced, and there is a problem that noise and damage to parts are caused due to the collision of the piston with the cover side.

  A cylinder with covers at both ends, an operating shaft that passes through one side cover and has a piston at the tip and reciprocates the cylinder, and the piston end surface or the cover end surface opposite to the operating shaft side In a hydraulic cylinder provided with a concave or convex portion that can be mated, and provided with a cushion mechanism by fitting the concave portion and the convex portion, the member having the concave portion or the convex portion is separated from the piston or the cover. Further, a fixing member is provided for fixing the concave portion or the member having the convex portion so as to be freely movable in a direction perpendicular to the axis with respect to the axis of the piston or the cover. The concave portion or the convex portion moves following the counterpart axis and damage during fitting can be avoided.

  According to the present invention, there is an effect of reducing the machining time by preventing the seizure and damage of the concave portion and the convex portion and relaxing the geometric tolerance of the component parts for regulating the misalignment between the concave portion and the convex portion.

BRIEF DESCRIPTION OF THE DRAWINGS It is the whole hydraulic cylinder block diagram (a) of this invention, and the attachment part enlarged view (b) of a flange. It is a partial block diagram of 2nd Example of this invention. It is a partial block diagram of the modification of this invention. It is a partial block diagram of the modification of this invention. It is a partial block diagram of the modification of this invention. It is a whole block diagram of the conventional hydraulic cylinder.

  A cylinder with covers at both ends, an operating shaft that passes through one side cover and has a piston at the tip and reciprocates the cylinder, and the piston end surface or the cover end surface opposite to the operating shaft side In a hydraulic cylinder provided with a concave or convex portion that can be mated, and provided with a cushion mechanism by fitting the concave portion and the convex portion, the member having the concave portion or the convex portion is separated from the piston or the cover. Further, a fixing member is provided for fixing the concave portion or the member having the convex portion so as to be freely movable in the direction perpendicular to the axis of the piston or the axis of the cover. Hereinafter, description will be made based on an embodiment shown in the drawings.

  A first embodiment provided by the present invention is shown in FIG. FIG. 1A is a longitudinal sectional view showing the entire configuration of a hydraulic cylinder according to the present invention, and FIG. 1B is an enlarged view of a portion A in FIG.

  As shown in FIG. 1 (a), the hydraulic cylinder 1 of the present invention includes a head cover 4 having a concave portion 9 which is perforated in an axial direction and communicates with a fluid inlet / outlet port 3a at one end of a cylinder (cylindrical body) 2. A rod cover 7 provided with a fluid inlet / outlet 3b provided with a bush 6 for supporting an operation shaft 5 described later, and a piston 8 that slides in a cylinder (cylindrical body) 2 in an airtight manner so as to be able to advance and retreat.

  The operation shaft 5 is integrally provided at the center of the end surface of the piston 8 on the rod cover 7 side, and the end surface of the piston 8 corresponding to the working fluid chamber B formed by the head cover 4 and the piston 8 is provided on the end surface of the piston 8. In addition, a flange 11 integrally provided with a convex portion 10 protruding in the axial direction is attached to the central portion.

  As shown in FIG. 1A, the tip of the convex portion 10 has a conical chamfered head to facilitate fitting into the concave portion 9. The flange 11 is provided with a mounting bolt hole 12 (described later) that penetrates the projection 10 in the axial direction. Further, a female screw 13 is threaded on the end face of the piston 8 to which the flange 11 is attached at a position corresponding to the mounting bolt hole 12.

  As shown in FIG. 1B, the mounting bolt hole 12 is drilled to an inner diameter that secures a clearance S in the direction perpendicular to the axis between the shoulder bolt 15 and the body C. Further, the length of the mounting bolt hole 12 is as described above. The threaded portion D of the shoulder bolt 15 is perforated to a length that secures an axial clearance H between the shoulder bolt 15 and the head end face F of the shoulder bolt 15 at a position where the shoulder portion E is in contact with the mouth of the female screw 13. Has been. Accordingly, the flange 11 is freely movable by the axial clearance H and the axial perpendicular clearance S while being fixed to the piston 8 by the shoulder bolt 15.

  The flange 11 having such a configuration is impossible in the radial direction while moving along the concave portion 9 with the movement of the piston 8 by the axial clearance G and the axial clearance H with respect to the misalignment between the concave portion 9 and the convex portion 10. The convex portion 10 can be fitted into the concave portion 9 without applying a load.

  The second embodiment provided by the present invention is a basic configuration of the hydraulic cylinder in the first embodiment, that is, a hydraulic cylinder that fits the convex portion into the concave portion.

  Specifically, as shown in FIG. 2, the hydraulic cylinder 20 of the present invention advances and retreats within the cylinder (cylindrical body) 21 and the head cover 23 having a fluid inlet / outlet port 22 a provided at one end of the cylinder (cylindrical body) 21. A through-hole communicating with the fluid inlet / outlet port 22a is provided in the end portion of the head cover 23 corresponding to the hydraulic fluid chamber B constituted by a piston 24 that is freely hermetically slid, and is provided with a concave cushion ring chamber G in the axial direction. A later-described cushion ring 26 having 25 is inserted, and at the end of the piston 24 corresponding to the hydraulic fluid chamber B, a convex portion 27 that fits into the through-hole 25 is integrally provided.

  The cushion ring 26 has an outer diameter that is smaller by an axially perpendicular gap S than the inner diameter of the cushion ring chamber G and a length that is smaller by an axial gap H than the axial depth. The elastic seal material 28 and the back end side end face are inserted into the cushion ring chamber G via the elastic seal material 29. Further, the cushion ring 26 is fixed so as to be freely movable by an axial perpendicular gap S and an axial gap H by a fixing member 31 fastened to the opening end face of the cushion ring chamber G with a bolt 30.

  The cushion ring 26 having such a configuration follows the convex portion 27 as the piston 24 moves in the axial direction due to the axial perpendicular clearance S and axial clearance H with respect to the misalignment between the through hole 25 and the convex portion 27. The convex portion 27 can be fitted without applying an excessive load in the radial direction while moving.

  The features of the cushion mechanism of the hydraulic cylinder provided by the present invention are as described above. However, the invention is not limited to the above and illustrated examples, and various modifications can be given.

  For example, as shown in FIG. 3, instead of the shoulder bolt 15, a concave flange chamber J is provided in the axial direction at the end corresponding to the hydraulic fluid chamber B of the piston 8, and the axis perpendicular to the inner diameter of the flange chamber J is provided. A flange 32 having a flange thickness smaller by an axial gap H than a flange outer diameter and an axial depth smaller by a directional gap S is inserted, and a fixing member fastened by a bolt 33 to the end face of the opening of the flange chamber J 34 can also be provided.

  As shown in FIG. 4, an axial recess 35 is formed at the end of the piston 8 corresponding to the hydraulic fluid chamber B, and a concave flange is formed at the end of the head cover 4 corresponding to the hydraulic fluid chamber B. A flange 37 having a passage 36 communicating with the fluid inlet / outlet port 3a at the center is inserted into the chamber L through an elastic seal member 38 on the outer periphery and an elastic seal member 39 on the bottom side end surface, and the opening end surface of the flange chamber L It is also possible to provide a fixing member 34 fastened with a bolt 33.

  Further, as shown in FIG. 5, a concave flange chamber M is provided at the end corresponding to the hydraulic fluid chamber B of the piston 8 and the cushion ring 26 of the second embodiment is inserted, and the hydraulic fluid chamber B of the head cover 4 facing the piston 8 is opposed. It is also possible to integrally provide a convex portion 40 provided with a passage 36 communicating with the fluid inlet / outlet port 3a at the center thereof at the end corresponding to. The present invention includes all of these modifications.

  The present invention can be implemented with general-purpose technologies and component configurations, and can be industrially used to improve safety and reduce noise.

1 Hydraulic cylinder 2 Cylinder (cylindrical body)
3a Fluid inlet / outlet 3b Fluid inlet / outlet 4 Head cover 5 Actuation shaft 6 Bush 7 Rod cover 8 Piston 9 Recess 10 Protrusion 11 Flange 12 Mounting bolt hole 13 Female screw 15 Shoulder bolt 20 Hydraulic cylinder 21 Cylinder (cylindrical body)
22a Fluid inlet / outlet port 23 Head cover 24 Piston 25 Through hole 26 Cushion ring 27 Protruding portion 28 Elastic seal material 29 Elastic seal material 30 Bolt 31 Fixing member 32 Flange 33 Bolt 34 Fixing member 35 Recess 36 Passage 37 Flange 38 Elastic seal material 39 Elastic seal Material 40 Convex 41 Head cover 42 Rod cover 43 Cylinder 44 Actuating shaft 45 Piston 46 Convex 47 Concavity B Working fluid chamber C Body D Screw part E Shoulder F Head end face G Cushion ring chamber H Axial clearance J Flange chamber K Actuation Liquid chamber L Flange chamber M Flange chamber S Right angle clearance

Claims (1)

  A cylinder with covers at both ends, an operating shaft that passes through one side cover and has a piston at the tip and reciprocates the cylinder, and the piston end surface or the cover end surface opposite to the operating shaft side In a hydraulic cylinder provided with a concave or convex portion that can be mated, and provided with a cushion mechanism by fitting the concave portion and the convex portion, the member having the concave portion or the convex portion is separated from the piston or the cover. A hydraulic cylinder characterized in that it is movable in a direction perpendicular to the axis of the axis of the cover.

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