JPH0654903U - Cushion device for hydraulic cylinder - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a cushion device for a hydraulic cylinder that is devised to reduce the number of parts and processed parts to simplify the configuration, and to devise a cushion operation and a check valve operation that are close to ideal. To aim. A cushion collar 2 fixed to a piston rod 1 has an outer end 3 opening to an outer end surface 4 of the cushion collar 2 and the cross-sectional area gradually decreases as the distance from the opening 5 further decreases. A recessed groove 8 having a length reaching or close to the inner end edge of the collar 2 and a notch 13 communicating with the inside and the outside are formed in the inner end surface, and the inner peripheral surface of the cushion collar 2 is recessed to form an annular space 10. Formed on the wall surface of the annular space 10 are a lead-out hole 11 communicating with the bottom surface of the lower portion of the concave groove 8 and an introduction hole 12 communicating with the bottom surface of the notch 13, and further the outer periphery of the inner end edge of the cushion collar 2. A seal surface 25 is formed on the inner surface of the seal, and a check rubber ring 24 is fitted on the seal surface 25.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cushion device for a hydraulic cylinder.

[0002]

[Prior art]

 Conventionally, as a cylinder with a cushion device of this type, a cylinder of the type shown in FIGS. 1 and 2 is described in JP-A-49-1978. In this type, oil flows in the direction of the white arrow as shown in Fig. 1 before the cushion device operates, and as shown in Fig. 2 while the cushion device is operating, the oil passage Is closed by the cushion collar 2 and the oil in the cushion chamber 22 is compressed to absorb the inertial force of the piston 14. At the time of this absorption, the cushion valve 23 functions as a throttle to suppress the movement up to the stroke end, thereby slowing the movement of the piston.

[0003]

[Problems to be solved by the device]

 The cushion device for the hydraulic cylinder described in the above-mentioned conventional technique has many parts and processed parts, and the structure is complicated, and there is a defect that the operation of the cushion and the operation of the check valve are not necessarily ideal. .

The present invention provides a new cushion device for a hydraulic cylinder, which is devised to reduce the number of parts and processed parts to simplify the configuration, and to make the cushion operation and the check valve operation closer to the ideal. That is the purpose.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, a cushion device for a hydraulic cylinder according to the present invention comprises a cushion collar 2 fixed to a piston rod 1, an outer end 3 of which is opened to an outer end face 4 of the cushion collar 2 and a cross-sectional area thereof. Is gradually reduced as the distance from the opening 5 increases, and further, the inner end is provided with a recessed groove 8 having a length reaching or close to the inner end edge of the cushion collar 2 and a notch 13 communicating with the inner end and the inner end. At the same time, the inner peripheral surface of the cushion collar 2 is recessed to form the annular space 10, and the wall surface of the annular space 10 is formed on the bottom surface of the guide hole 11 and the notch 13 communicating with the bottom surface of the lower portion of the concave groove 8. The communicating hole 12 is opened, and a seal surface 25 is further formed on the outer periphery of the inner end edge of the cushion collar 2. The seal surface 25 is fitted with a check rubber ring 24.

[0006]

【Example】

 In the embodiment of the present invention shown in the drawing, an outer end 3 is opened on an outer peripheral surface of a cushion collar 2 fixed to a piston rod 1, and an outer end 3 is opened to an outer end surface 4 of the cushion collar 2, and the cross-sectional area is gradually reduced as the distance from the opening 5 is increased. Further, a concave groove 8 having a length such that the inner end reaches the inner end edge of the cushion collar 2 and a notch 13 communicating with the inside and the outside are formed on the inner end face, and both end portions 9 of the inner peripheral face of the cushion collar 2 are formed. , 9'are recessed to form an annular space 10, and an outlet hole 11 communicating with the bottom surface of the concave groove 8 and an introduction hole 12 communicating with the bottom surface of the notch 13 are formed on the wall surface of the annular space 10. After the opening, the outer periphery of the inner end edge of the cushion collar 2 is obliquely cut to form a concave annular seal surface 25, and the check rubber ring 24 is fitted to the seal surface 25.

In this embodiment, the oil flows only through the main path passing through the concave groove 8 to perform the cushion function during the entire period of the operation of the cushion device, and during the cushion function, The rubber ring 24 is tightly fitted to the concave annular sealing surface 25 to keep the auxiliary path closed, and when the piston 14 is returned upward, the internal pressure of the auxiliary path increases the diameter of the rubber ring 24. The auxiliary route is kept open.

[0008]

[Action]

 The flow of hydraulic pressure when the cushion is operated is discharged to the outside through the cushion chamber 22 → the concave groove 8. At this time, the check rubber ring 24 is pushed into the gap between the side surface of the piston 14 and the seal surface 25 by the internal pressure of the cushion chamber 22, and the hydraulic pressure is forced to flow from the cushion chamber 22 to the concave groove 8. Further, the hydraulic pressure flow at the time of operating the check valve enters the cushion chamber 22 through the external inflow, the concave groove 8, the outlet hole 11, the annular space 10, the inlet hole 12, the notch 13, the rubber ring 24, and the sealing surface 25. When the check rubber ring 24 is operated, a large amount of oil is supplied to the cushion chamber 22, and the piston 14 moves upward in FIG. 3 at a high speed ignoring the cushion operation.

[0009]

[Effect of device]

 The cushion device for a hydraulic cylinder according to the present invention eliminates a throttle valve by providing a concave groove 8 on the outer peripheral surface of the cushion collar 2 with a length such that the inner end reaches the inner end of the cushion collar 2. The check valve is simplified by providing 8, the outlet hole 11, the annular space 10, the introduction groove 12, the notch 13, the sealing surface 25, and the check rubber ring 24, so that the cushion operation and the check valve operation can be made closer to the ideal. It has the effect of being able to completely achieve the intended purpose.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a cushion device for a hydraulic cylinder according to the present invention in an operating state.

FIG. 2 is a perspective view showing a cushion ring in the embodiment.

FIG. 3 is a cross-sectional view showing a conventional example.

FIG. 4 is a sectional view showing the same operating state.

[Explanation of symbols]

 1 Piston rod 2 Cushion collar 3 Outer end 4 Outer end surface 5 Opening 7 Inner end surface 8 Recessed groove, 9 Both end points 9'Both end points 10 Annular space, 11 Outlet hole 12 Introducing hole 13 Piston 15 Piston ring 16 Check plug 17 Check spring 18 Check pole 19 Head cover 20 Cylinder tube 21 Cushion 22 Cushion chamber 23 Cushion valve 24 Rubber ring, 25 Sealing surface

Claims (1)

[Scope of utility model registration request] 1. A cushion collar 2 fixed to a piston rod 1 has an outer end 3 opening to an outer end surface 4 of the cushion collar 2 and the cross-sectional area gradually decreases as the distance from the opening 5 further decreases. A recessed groove 8 having a length reaching or close to the inner end edge of the cushion collar 2 and a notch 13 communicating with the inside and the outside are formed in the inner end surface, and the inner peripheral surface of the cushion collar 2 is recessed to form an annular space. 10
Is formed on the wall surface of the annular space 10, and a lead-out hole 11 communicating with the bottom surface of the lower portion of the concave groove 8 and an introduction hole 12 communicating with the bottom surface of the notch 13 are formed. A sealing surface 25 is formed on the outer circumference, and this sealing surface 2
5. A cushion device for a hydraulic cylinder, characterized in that a check rubber ring 24 is fitted to the member 5.