JPH0412246Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a cushion device for a hydraulic cylinder.

[Conventional technology]

This type of conventional technology is shown in Fig.
152803).

In Fig. 2a, 1 is a cylinder tube of a hydraulic cylinder A, and a supply/discharge port 7 is provided at the end of the cylinder tube.
A head 2 having a shape is fixed. 3 is a piston rod, and a piston 5 which is slidably fitted into the cylinder tube 1 is fixed by a nut 5a. At the end 4 of this piston rod 3,
A cushion rod 6 is provided, and the head 2 is provided with a hole 7 which opens into the head side pressure chamber V at a position into which the cushion rod 6 is slidably inserted.

The cushion rod 6 has a base end 9 that is inserted into the mounting hole 8 provided at the end 4 of the piston rod 3, and a groove 10a for cushioning on the outer periphery.
Cushion part 10 having a tapered part 10b at the tip
It is made up of.

Between this cushion part 10 and the base end part 9,
As shown in FIG. 2b, a groove 11 is provided, and the right end 11a of this groove 11 holds a C-shaped retaining ring 12 with a circular cross section, whose half is inserted into the groove 8a of the mounting hole 8 and held. engage. In addition, the right end 9a of the base end 9
comes into contact with the bottom surface 8b of the mounting hole 8. The groove 8a of the mounting hole 8 is formed with a concave portion having the same shape as the semicircular portion of the retaining ring 12, and as shown in FIG. 2b, half of the retaining ring 12 is inserted and secured. It's becoming like that. In addition, the bottom surface 8b of the cushion rod 6
The end 11a located slightly to the right of the right end of the groove 8a and the end 4a of the piston rod 3
A gap 4b slightly larger than the diameter of the retaining ring 12 between the
and an end portion 11b forming a depth 11h.
is made slightly larger than the diameter of the retaining ring 12.

With the above configuration, the cushion rod 6 is attached to the end 4 of the piston rod 3 as shown in FIG. 2a.
To install, first insert the base end 9 and the right end 9a into the bottom surface 8b of the mounting hole 8 until they abut, then insert the retaining ring 12 into the groove 11, and press it with a tool to push it into the groove of the mounting hole 8. Insert until it fits into 8a.

In the cushion device configured as described above, when the piston 5 moves from the right to the left in FIG. In this way, as the piston 5 moves leftward and the cushion portion 10 of the cushion rod 6 begins to fit into the hole 7, the flow of pressure oil in the head side pressure chamber V is directed to the throttle groove 10.
A cushion acts on the piston 5 as it is squeezed at point a.

The cushion rod 6 is pressed to the right when the constricted portion 10a of the cushion rod 6 begins to fit into the hole 7, so that the right end 9a of the base end 9 comes into contact with the bottom surface 8b. Then, when the oil pressure in the head side pressure chamber V increases (due to the action of the cushion), the oil pressure acts on the mounting hole 8, so the cushion rod 6
is pressed in the direction of the hole 7 by the hydraulic pressure acting on its cross-sectional area. This force has an effect on the end 11 of the groove 11.
a is adapted to engage with and correspond to the retaining ring 12.

[Problem that the invention attempts to solve]

In the above-mentioned prior art, when the cushion rod 6 is attached to the attachment hole 8 provided in the end portion 4 of the piston rod 3, a retaining ring 1 with a base end 9 disposed in the attachment hole 8 is used.
2, it is uncertain whether the retaining ring has been set securely, and furthermore, the second
As shown in Figure b, the right end 11a of the groove 11 of the cushion rod 6 presses near the center of the retaining ring, so there is a possibility that the retaining ring will come off due to that force.

[Means for solving problems]

The present invention solves the above problems by providing a hole in the head that opens into the head side pressure chamber of the hydraulic cylinder and communicating with the supply/discharge passage, and a cushion rod that has a cushion portion that is slidably fitted into the hole. Loosely fit the base end into the mounting hole provided at the end of the piston rod, fit a retaining ring with a circular cross section into the groove formed in the predetermined location of this mounting hole, and fix the base end. In a hydraulic cylinder cushioning device in which a groove is provided in a part of the piston rod to which the retaining ring engages, and the cushion rod is attached to the piston rod by the retaining ring,
The groove at the base end is large enough to allow the retaining ring to fit loosely, and the side end of the head side pressure chamber of the groove fits into the mounting hole when the end of the cushion rod and the bottom of the mounting hole come into contact. An end located between the end of the provided groove on the side of the head side pressure chamber and a part separated by a distance corresponding to the radial dimension of the retaining ring in the direction of the head side pressure chamber, and opposite to this end. The retaining ring is provided with an abutting portion that abuts on the inner side of the center diameter of the retaining ring.

[Effect]

According to the above-mentioned means of the present invention, in order to attach the cushion rod to the attachment hole provided at the end of the piston rod, first insert a part of the base end into the attachment hole, and then insert the retaining ring into the base end. Insert it into the groove provided, press the retaining ring to elastically deform the entire body, and insert it into the mounting hole. Next, press the cushion rod so that its end surface comes into contact with the bottom surface of the mounting hole. Then, since the center of the retaining ring is located to the right of the left end of the groove provided in the mounting hole, the retaining ring can be automatically set in the groove of the mounting hole. Further, when the cushion rod is pressed by the pressure during the cushion action, the abutting portion at the base end acts to push the retaining ring from the inside to the outside.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1a showing an enlarged view of the main part, 4 indicates the end of the piston rod 3 shown in FIG. There is. In this mounting hole 20,
A groove 21 having a semicircular cross section is provided approximately in the center thereof into which half of the retaining ring 12 is inserted.

Reference numeral 22 denotes a cushion rod, only a portion of which is shown, but the cushion portion is provided with a cushion portion having the same function as shown in FIG. 2a.
A proximal end portion 23 is provided that loosely fits into the 0. This base end portion 23 is provided with a groove 24 into which the retaining ring 12 can be loosely fitted.

The above-mentioned groove 24 of the base end 23 has an end 24a on the head side pressure chamber V side and a contact portion 24c that contacts the retaining ring 12 on the side opposite to this end 24a.
It has an end portion 24b provided with. The end 24a of the groove 24 is connected to the proximal end 2 as shown in FIG.
When the end surface 23a of the retaining ring 12 comes into contact with the bottom surface 20a of the mounting hole 20, a portion closer to the head side pressure chamber by the radius dimension r of the retaining ring 12 than the end 21a of the groove 21 on the side of the head side pressure chamber V. As shown in FIG. 1a, when the proximal end 23 of the cushion rod 6 is pressed to the left, Abutting part 24c (arc part) that comes into contact with part 25a of
The cross section is approximately 1/4 semicircle, which is large enough to loosely fit the retaining ring 12.

In the cushion device having the above configuration, in order to attach the cushion rod 6 as shown in FIG. 1a, the retaining ring 12 is elastically deformed as shown in FIG. The first
Push until the end surface 23a of the base end portion 23 comes into contact with the bottom surface 20a of the mounting hole 20, as shown in FIG. Then, the center 12e of the retaining ring 12 is pushed by the end 24a and becomes to the right of the end 21a of the groove 21. Therefore, when the retaining ring 12 is fitted into the groove 21, the end 2
4a and the retaining ring 12 are no longer in contact with each other. In the cushion device installed in this manner, when the cushioning action is performed and the head side pressure chamber V is pressed in the direction of arrow E in FIG. Groove contact portion 24
The retaining ring 12 acts to prevent the cushion rod 6 from falling off.

〔effect〕

This invention allows the retaining ring to be inserted into the mounting hole of the piston rod together with the retaining ring by using the groove provided at the base end of the cushion rod, and simply by bringing the end surface of the base end into contact with the bottom of the mounting hole. can be installed in the groove of the mounting hole. After installation, the end of the groove and the retaining ring are separated, and when the cushion rod is in action,
The abutting portion of the groove acts to spread the retaining ring.
Therefore, the cushion rod can be easily attached, and it is possible to reliably prevent the cushion rod from falling off.

[Brief explanation of the drawing]

FIG. 1a is a partial sectional view showing an embodiment of the present invention, FIGS. 1b and 1c are partial sectional views of FIG. 1a, and FIG. 2a is a sectional view of the prior art. Figure 2b
is a partially enlarged view of FIG. 2a. 1...Cylinder tube, 2...Head, 3...
... Piston rod, 4 ... End, 5 ... Piston, 6, 22 ... Cushion rod, 7 ... Hole,
8, 20... Mounting hole, 9, 23... Base end, 10
...Cushion part, 12...Retaining ring, 21, 8a
...Groove, 24...Groove, 24a...End, 24b...
... End portion, 24c... Contact portion, A... Hydraulic cylinder.

Claims (1)

[Scope of utility model registration request] A mounting method in which the head is provided with a hole that opens into the head side pressure chamber of the hydraulic cylinder and communicates with the supply/discharge passage, and the proximal end of a cushion rod having a cushion portion that is slidably fitted into the hole is provided at the end of the piston rod. A retaining ring having a circular cross section is fitted loosely into the hole, and a retaining ring having a circular cross section is fitted into a groove formed at a predetermined location of the mounting hole, and a groove is provided at the base end in which the retaining ring engages. In a hydraulic cylinder cushioning device in which the cushioning rod is attached to the piston rod with a retaining ring,
The groove at the base end is large enough to allow the retaining ring to fit loosely therein, and when the end of the groove on the head-side pressure chamber side contacts the end of the cushion rod and the bottom of the mounting hole, the groove fits into the mounting hole. located between the end of the groove provided on the head side pressure chamber side and a part separated by a distance corresponding to the radial direction of the retaining ring in the direction of the head side pressure chamber, and facing this end. A hydraulic cylinder cushioning device having a structure in which an abutment part is provided at the end of the retaining ring to abut inside the center diameter of the retaining ring.